Choosing industrial displays with care

Display 3Sourcing displays direct from the Far East seems easier than ever, but as specialist distributor, Display Technology, points out, the associated risks have not diminished.

As communication links improve, the ability to source thin film transistor liquid crystal displays and touch screen products directly through Far Eastern sources has become easier; emails arrive daily offering deals that seem impossible to refuse.

Just as a sensible consumer would not buy a branded watch from a market stall, however, industrial TFT LCD purchasers would be unwise to follow these leads. In the same way that they would want to know their watch was genuine, rather than a production line reject, they will want their display to meet acceptable quality standards. There are many factors involved, including price, but it is important to consider the overall cost of ownership.

Focus on quality
During TFT manufacture, there are always quality levels in place. Anything that does not meet these standards, due to an unacceptable number of dead or bright pixels or dry joints, for example, will be classified at a lower quality level. These panels are not scrapped, but often sold cheaply or auctioned off into local Far Eastern markets for use in unbranded consumer products.

Unfortunately, Far East dealers will often source these at low prices and target the European markets where profits are higher. Sometimes even reputable display specialists source these lower grade displays at a commercially attractive price, but purchasers can only guarantee the source and quality when buying through an official distributor.

Continuity of supply
Major manufacturers will have hundreds of parts in their portfolio, but will only support a small fraction of industrial panels through distribution. This is due to the level of support required and the longevity of supply. A distribution partner will have direct dialogue with the manufacturer, as well as access to roadmaps, and can direct the initial design to a stable product. Distributors can also pre-warn customers of any possible issues in delivery or potential end of life scenarios. Certain markets, including medical and military, have a stringent approval process and any changes can be expensive and time consuming, so continuity of supply is critical.

Look at lead times
Naturally, end manufacturers need to keep stock low, with short lead times also taking on major importance. To achieve this, it is critical to purchase through supply partners that can be flexible with stock holding. Some TFT LCD suppliers have notoriously long lead times, going out to 20 weeks. Unfortunately, these tend to be the suppliers who offer premium displays with the strongest continuity statements. It is therefore important that a chosen supplier has the financial ability, flexibility and spread of customers to support the brief.

Total support
TFT LCDs are normally just one part of a design. A good display specialist will therefore offer support products including touchscreens, cables and analogue-to-digital interface embedded boards. Services should also include optical bonding of touch screens in a clean room environment, bespoke touchscreen design and kitting.

Buying through the grey market can reward with some attractive ‘front end’ pricing, but it is important to look at the whole picture, including quality or support issues. Dealing with an authorised or franchised reseller ensures the best commercial pricing, as well as providing peace of mind for the future.